Tools/tips for easily change a module/function namespace

Hi, i am currently in the middle of refactoring effort, and part of that effort was changing file/schema/module namespace into a more proper namespace, for example changing a module from LoadService.V2.Loads.Schema.JobPreassignedTransporterCompanyData to LoadService.V2.DeliveryOrderManagement.Schema.JobPreassignedTransporterCompanyData.

I found a lot of difficulties in trying to find out which file / module that call LoadService.V2.Loads.Schema.JobPreassignedTransporterCompanyData previously, especially because there is a lot of way to alias a module and call it in Elixir, for example:

  1. direct call (easiest to find):
LoadService.V2.Loads.Schema.JobPreassignedTransporterCompanyData.some_function
  1. alias direct module:
alias LoadService.V2.Loads.Schema.JobPreassignedTransporterCompanyData
JobPreassignedTransporterCompanyData.some_function
  1. alias parent module
alias LoadService.V2.Loads.Schema
Schema.JobPreassignedTransporterCompanyData.some_function

What better ways i could do to make this process of finding & renaming module namespace better?

Refactoring is not the sweet spot of elixir, having no static typing and no refactoring tools (that I know of).

1+2 should be easy to handle with search+replace, right?
3 I avoid exactly because of this. The best I can come up with is

  • search alias LoadService.V2.Loads.Schema in all files
  • replace it if JobPreassignedTransporterCompanyData is the only thing using Schema here, otherwith add the new module alias

I’m curious if there are better solutions…

Yes, that’s what i currently do also, try to find & replace manually as best as i could, but it get really hard if the module name is short & common (for example, i have schema called Job).

one idea i was thinking of if there is some way to manipulate compiler trace feature to help discover which file/module that call a particular file / module. but i sadly lacking a lot of knowledge to do it in short time period.

(Now that i think about it, maybe i could use elixir warning message when trying to call a undefined function/module as indicator, let me check a bit and see it).

Yes, I think this is just very hard (or rather tedious) to do without any tool-support.
Can’t say anything about how a refactoring tool could be implemented in Elixir, because its just beyond me.

Oh, turn out warning emitted by compiler is useful for catching when refactoring namespace if there’s any missed rename. i currently would

mix clean
mix test &> mix_test_result.txt
# wait a bit + check mix_test_result.txt periodically to ensure all code + test code get compiled, but skip actual testing execution to get compiler warning

if i miss some renaming, it would show up in mix_test_result.txt like

warning: LoadService.V2.DeliveryOrderManagement.Schema.JobPreassignedTransporterCompanyData.btms_send_transporter_exclusive_shipment_notifications/2 is undefined or private
lib/load_service/v2/loads/api/delivery_order.ex:2614: LoadService.V2.Loads.API.DeliveryOrder.save_delivery_order/3

4 Likes

A bit of update, turn out that mix has a functionality for tracking caller of a particular module via xref, it can be used to note which file that need to be changed, though it does require full recompilation of code from every invocation, like

mix xref callers LoadService.V2.Loads.JobPreassignedTransporterCompanyData
(…recompile whole application)
lib/load_service/v2/delivery_order_management/jobs.ex (runtime)
lib/load_service/v2/loads/api/delivery_order.ex (runtime)
lib/load_service/v2/oban/job.ex (runtime)